1. Field of the Invention
This invention relates to a tape-like, pressure sensitive label strip for use in a label printing and dispensing machine (hereinafter referred to simply as a "label printing machine"). More particularly, the invention relates to the feeding cuts in the label strip by which the label strip is advanced in the label printing machine as they are engaged with the feeding pins formed on a feeding roller.
2. Description of the Prior Art
A label strip of the type to which the invention relates comprises one elongated length of label material, which has an imprintable top surface and an adhesive coated rear surface, and it comprises a second elongated length of backing material with a release material surface to which the adhesive coated surface of the label material is applied.
There are two common systems in use for advancing label strips by using feeding pin rollers. In the label strip folding edge system, the complete two layer label strip is directed forward of the platen of the label printing machine and the backing material of the label strip is folded rearward in front of the platen. Only the strip of backing material is then brought into engagement with the pins of a feeding roller that is located to the rear of the platen. Rotation of the feeding roller in engagement with the label strip backing material pulls the whole label strip forward through the machine. Label pieces from the strip of label material are peeled from the strip of backing material at the label strip folding edge in front of the platen.
In the other push-separate-pull system, the complete two layer label strip is first engaged by the feeding pins of a feeding roller (first engagement section) before the label strip has reached the platen. This pushes the whole label strip forward. The layer of backing material is then folded into a loop in the narrow space of a folding section in front of the platen. As in the folding edge system, only the layer of backing material is brought into engagement with the feeding pins of the feeding roller (second engagement section), and the layer of backing material is then dragged through the label printing machine. In this system the label pieces are also peeled from the backing material in the folding section in front of the platen.
In both systems, the strip of backing material is folded back and is brought into engagement with the pins of the feeding roller at least once for advancing the label strip.
In order to engage the label strip, which is comprised of laminated layers of a label material and a backing material, with the feeding pins of a feeding roller, the label strip must be provided with some feeding cuts. Such cuts are disclosed, for example, in U.S. Pat. No. 3,501,365. In conventional layered label strips of the above described kind, the feeding cuts in the label strip form feed roller pin engageable feeding tongues to be engaged by the feeding pins of the roller. The cuts are oriented such that the free or cut end portions of feeding tongues that are formed in the strip of backing material are oriented toward the front or downstream side or advancing direction of the advancing label strip, while the connecting or uncut attached portions of the feeding tongues are oriented toward the rear or upstream side or trailing direction of the advancing label strip.
When the feeding tongues in the strip of backing material are formed in the conventional manner by cutting the forward ends of the tongues, the feeding tongues are liable to be pushed fully upright owing to the forward inertia of the backing material during the peeling of labels which occurs through the rearward folding of the backing material. Especially when the label strip is being advanced rapidly, the feeding tongues are raised upright, and they contact the bottom cover of the label printing machine. This may cause the cut ends of the feeding tongues to be torn just after being folded rearwardly. Owing to this tearing of the feeding tongues, the later engagement of the strip of backing material with the pins of the feeding roller becomes impossible, and the label strip cannot be advanced through the machine.